The words, however, are in Arabic, Farsi, Pashto or some other language that few Americans understand. The messages urgently need to be translated, but there aren't enough expert linguists to handle the flood.

The time for robot translators has arrived, according to a panel of language specialists at a recent meeting of the American Association for the Advancement of Science.

"The Defense Department doesn't have enough human translators," said Melissa Holland, an expert at the Army Research Laboratory in Arlington, Va.

Since Sept. 11, 2001, the Defense Department, the CIA and other intelligence agencies have been pouring money and effort into what's known as "machine translation," or MT for short.

MT uses computers to translate messages from one language to another – such as turning "Good morning" into "Buenas dias" or "Auf wiedersehen" into "Au revoir" – with little or no human intervention.

Computer scientists have labored to perfect machine translation since the 1950s, with only modest success. But the Sept. 11 terrorist attacks and the wars in Afghanistan and Iraq have given the technology a boost.

Today's robot linguists are far from perfect, but they can give soldiers in the field the gist of a document, a poster or a possible threat scrawled on a wall.

"Soldiers can get a sense of what a document is about – not a perfect translation," Holland said. Accuracy is still less than 50 percent, said Clare Voss, another Army researcher.

Equipped with a handheld PDA, a digital camera and a laptop computer in the back of a Hummer, a soldier can quickly decide if a message needs human attention.

"Expectations for speed and accuracy are not always met – it's not the Queen's English," admitted William McClellan, an MT systems manager at Booz-Allen Hamilton, a technology consulting firm in McLean. "But it's a way to find the needle in the haystack without translating every straw."

The volumes of material to be translated are enormous, said Mark Turner, an MT expert at Maryland information technology firm CACI.

In Baghdad, "we found warehouses with billions of documents in bags, boxes, binders and books," he said. "There are tons of paper and terabytes (trillions of bytes or letters) of electronic media."

For decades, machine translation systems labored to make computers understand traditional rules of grammar – subjects, verbs, objects and so on. Progress was slow, thanks to the tremendous ambiguity and complexity of human language.

The word "get," for example, has 24 possible meanings listed in Webster's New College Dictionary. One of them is "kill" – as in "I'll get you for this."

In the 1990s, however, a new technique came along, applying statistical analysis to huge databases of previously translated texts. By comparing a new, unknown message to millions of stored sentences, phrases and words, researchers could quickly find the most likely translation.

The method, also known as "data-driven machine translation," works like this: The computer scans a sentence, lists each possible meaning of each word and arranges them in every possible order, most of them nonsensical, until it finds one that most nearly matches a good translation.

Machine translation is also gaining ground in international commerce, said Stephen Richardson, a former IBM researcher who now heads the Machine Translation Project at Microsoft. Nevertheless, the prime movers for machine translation are the war on terror and the urgent need to understand what potential enemies are saying.

"The backlog of untranslated documents is a hindrance to the war on international terrorism," said Mohammad Shihadah, the founder of Applications Technology, a small Virginia firm that sells Arabic-to-English translation software to the government.